Walking Dead is probably the "better" game for the "serious" player. Very intense, very brutal, very deep. Probably the most adrenaline filled wizard mode ever (Horde). Layout is unique and good, but most shots end up in the pop bumpers slowing down flow. Very heavy focus (modes AND bloodbath) on the drop targets which are difficult, dangerous, and not terribly satisfying to hit. Can be super frustrating 95% of the time, but extremely satisfying when you get it rocking. Will be both your most hated game and your most loved game in the course of any given day. Lighting it on fire crossed my mind often when I owned it. Finally sold it when I got sick of it's crap, but now wish I had it back.
Deadpool is the more FUN game. Light hearted...lots of humor. Much better art. Not as deep, but still plenty to do for all skill levels. Clever rules with great animations, especially if you are an old-school video game lover. Unique layout with one of the best ramp/lock shots ever, though it is not a gimme shot. Will bring a big stupid smile to your face every time you play, whether you have a good game or not. Recent code updated have taken it from good to great, and they aren't done yet.
I'd go Deadpool, especially when considering the family, but even if just for myself. TWD is also a great game though. Can't lose with either. Since you are replacing Funhouse, a game the family likes, I would say Deadpool is closer in thematic "feel" (lighthearted, humor, heavy on character, getting poked fun at, etc) than TWD would be.
Hit 'em with the BOOM!